Betsy von Furstenberg, a glamorous German-born baroness who made her debut in the movies and on the Broadway stage in the early 1950s as a teenager and later reinvented herself as a television actress, writer and philanthropist, died on April 21 at her home in Manhattan. She was 83. She is pictured in 1968 with Keith Baxter in “Avanti!” at the Booth Theater in New York. Her half-brother was Egon von Furstenberg, first husband of designer Diane von Furstenberg. When I met Egon years ago on the beach in Mykonos, he introduced himself by saying, “Hello. I’m Egon. I’m a Prince.” The obvious response was: “Hello. I’m Brendan. I’m a Queen.” But I said, simply, “Nice to meet you.”